Just wanted to point out that this comment is outdated. Obj models CAN support animations if using Blender. Another user stated this below, too.
– KrythicDec 8 '15 at 14:51

1

@Krythic It is not out of date; animation support has not been added to to the .obj format. Any static image format can be used as an animated format with one file per frame, or anything that you could do interpolation with could use one file per keyframe; but just because you can animate a directory full of static JPEGs doesn't mean that JPEG supports animation.
– Brian CampbellDec 9 '15 at 0:30

Blender 2.63 can export animations in .obj, with each keyframe (as hypothesized above)
being a complete .obj of it's own. Blender can handle this export func relatively quickly and efficiently. So 1, Blender is an excellent working proof of concept, and two, Blender may actually help you out code wise (it's open source and you can redistribute any edited code source), allowing you to completely bypass writing your own efficient, quick support for this operation.

Is it also possible to import multiple .obj or .dae keyframes in Blender so we can view the animation? This would be useful for vertex animation, so we don't need to create a custom tool to view the animation.
– baptxDec 17 '18 at 16:46

Indeed, an animation with multiple keyframes can be exported as a single OBJ file, that's what a reverse engineering project for Spyro games is doing to play characters animations from an OBJ file (klimaleksus.narod.ru/Files/6/MoreSpyroModels.rar).
– baptxSep 8 '18 at 10:34